Quantum efficiencies exceeding unity due to impact ionization in silicon solar cells

This is the authors' abstract. We don't add key points for this paper.

Absolute measurements demonstrate internal quantum efficiencies in silicon solar cells to exceed unity for photon energies above the first direct band gap and to show distinct spectral features that correspond to specific points in the Brillouin zone. Ultraviolet radiation can generate hot carriers with sufficient energy to cause impact ionization which results in two electron hole pairs per incident photon.